A conventional method for identifying a user by voice information has been proposed. Patent Literature 1, for example, discloses a method for estimating the ages and genders of viewers, as well as the relationship between the viewers, based on temperature distribution information and voice information, and selecting viewing content by taking into consideration the adaptation to the place, time zone or the like. In this manner, this method provides viewing contents suitable for the viewers and places.
On the other hand, Patent Literature 2, for example, describes that voice data of a plurality of specific speakers are registered together with speaker identification information for specifying the speakers, and that the similarity between the registered voice data and input voice data is calculated to recognize the voices of the speakers.
Unfortunately, an easier way to identify an individual by voice information has not yet been studied.